The University of California, San Francisco (UCSF) Latino Mental Health Research Program, based at San Francisco General Hospital (SFGH), proposes to develop evidence-based Internet interventions in Spanish and English to prevent major depressive episodes (MDEs). The current pilot project has three aims designed to set the stage for a subsequent randomized control trial of such an Internet intervention: Aim 1. Adaptation of a widely tested cognitive-behavioral intervention for Internet administration, and creation of a self-help research Website that will automatically recruit participants online, deliver the intervention online, and conduct follow-up assessments online. Aim 2. Usability testing of the Website with Spanish- and English-speaking men and women from public sector health clinics to assess and optimize, prior to launching the online pilot study: accessibility to as wide a range of individuals as possible, to reduce disparities;understanding of informed consent for the study;and understanding of the various study measures (i.e., measures of depression, self-efficacy, and so on). Aim 3. Conducting a nationwide online pilot study of the site in Spanish and English to examine: recruitment rates, response rates to specific ads to identify best recruitment strategies, and characteristics of responders;information on the effectiveness of informed consent procedures to enhance understanding of key aspects of the study;utilization patterns of each element of the site;and efficacy of methods to reduce follow-up attrition. This application is responsive to NIMH Strategic Objective 3 (to develop new and better interventions that incorporate the diverse needs and circumstances of people with mental illnesses) and Objective 4 (to strengthen the public health impact of NIMH-supported research). The Internet intervention would provide a highly innovative means of delivering preventive mental health services for undertreated and underserved populations. An online intervention of this type has the potential to reach millions of individuals nationally and internationally, thereby maximizing the public health benefit of NIMH funding. PUBLIC HEALTH RELEVANCE: Major depression affects millions of people and is the number one cause of disability worldwide. An Internet intervention that prevents depression and that can reach at-risk individuals in their own language, 24 hours a day, anywhere with Web access, would greatly increase mental health outreach in the U.S. and beyond. The scalability of such an intervention could also make it very cost effective as a public health measure.